Tools

Tag: isLetter

In the previous example you’ve learned how to use the Character.isDigit() method to check if a character representing a digit.

In this example you will learn how to check if a character representing a letter. You can use the Character.isLetter(char c) method to check if a character is a valid letter. This method will return a true value for a valid letter characters and false if the character is not a valid letter.

In the code snippet below you will also learn how to use the toCharArray() method to covert a string into an array of char. Here we use the method so that we can check every character in the for-each loop to see is the character is a letter or not.

package org.kodejava.example.lang;
public class CharacterIsLetterExample {
public static void main(String[] args) {
String name = "Kode Java 123";
// Determines if the specified character is a letter
if (Character.isLetter(name.charAt(5))) {
System.out.println("The fifth character (" +
name.charAt(5) + ") is an alphabet!");
}
// Iterates all characters in the string to see if it is
// a letter or not.
for (char c : name.toCharArray()) {
if (Character.isLetter(c)) {
System.out.println(c + " is a letter.");
} else {
System.out.println(c + " not a letter.");
}
}
}
}

The code will print the following output:

The fifth character (J) is an alphabet!
K is a letter.
o is a letter.
d is a letter.
e is a letter.
not a letter.
J is a letter.
a is a letter.
v is a letter.
a is a letter.
not a letter.
1 not a letter.
2 not a letter.
3 not a letter.